Rhodamine dyes

ABSTRACT

Novel compounds of the general formula I ##STR1## where A.sup.⊖  is an anion, R is hydrogen or unsubstituted or substituted alkyl or cycloalkyl, R 1  and R 2  independently of one another are each hydrogen or unsubstituted or substituted alkyl or cycloalkyl, or one of the radicals may furthermore be aryl, or R 1  and R 2 , together with the nitrogen atom, form a saturated heterocyclic structure, the radicals R 3  independently of one another are each hydrogen or C 1  -C 4  -alkyl, R 4  and R 5  independently of one another are each unsubstituted or substituted alkyl or cycloalkyl, or one of the radicals may furthermore be hydrogen, aryl or hetaryl, R 4  and R 5 , together with the nitrogen atom, form a saturated heterocyclic structure, n is 1, 2 or 3, X is hydrogen, chlorine, bromine, C 1  -C 4  -alkyl, C 1  -C 4  -alkoxy or nitro and Y is hydrogen or chlorine, are particularly useful for dyeing paper stocks.

The present invention relates to compounds of the general formula I ##STR2## where A.sup.⊖ is an anion, R is hydrogen or unsubstituted or substituted alkyl or cycloalkyl, R¹ and R² independently of one another are each hydrogen or unsubstituted or substituted alkyl or cycloalkyl, or one of the radicals may furthermore be aryl, or R¹ and R², together with the nitrogen atom, form a saturated heterocyclic structure, the radicals R³ independently of one another are each hydrogen or C₁ -C₄ -alkyl, R⁴ and R⁵ independently of one another are each unsubstituted or substituted alkyl or cycloalkyl, or one of the radicals may furthermore be hydrogen, aryl or hetaryl, R⁴ and R⁵, together with the nitrogen atom, form a saturated heterocyclic structure, n is 1, 2 or 3, X is hydrogen, chlorine, bromine, C₁ -C₄ -alkyl, C₁ -C₄ -alkoxy or nitro and Y is hydrogen or chlorine.

Unsubstituted or substituted alkyl or cycloalkyl radicals R, R¹ and R² are, for example, C₁ -C₁₃ -alkyl which may furthermore be substituted by hydroxyl, C₁ -C₁₃ -alkoxy, chlorine, cyano, phenyl, tolyl, chlorophenyl or methoxyphenyl and may be interrupted by oxygen, and C₁ -C₄ -alkylsubstituted cycloalkyl. Specific examples are CH₃, C₂ H₅, C₃ H₇, C₄ H₉, C₅ H₁₁, C₆ H₁₃, C₈ H₁₇, C₁₀ H₂₁, C₁₂ H₂₃, C₁₃ H₂₅, ##STR3## C₂ H₄ OH, C₃ H₆ OH, C₂ H₄ OCH₃, C₂ H₄ OC₂ H₅, C₂ H₄ OC₃ H₇, C₂ H₄ OC₄ H₉, C₃ H₆ OCH₃, C₃ H₆ OC₄ H₉, C₂ H₄ OC₂ H₄ OCH₃, C₂ H₄ OC₂ H₄ OC₂ H₅, C₂ H₄ OC₂ H₄ OC₄ H₉, CH(CH₃)CH₂ OC₂ H₄ OCH₃, CH₂ CH₂ Cl, C₂ H₄ CN, CH₂ C₆ H₅, C₂ H₄ C₆ H₅, CH₂ C₆ H₄ CH₃, CH₂ C₆ H₄ Cl, CH₂ C₆ H₄ OCH₃, CH₂ C₆ H₃ (CH₃)₂, cyclopentyl, cyclohexyl and methylcyclohexyl. The empirical formulae apply to the n- and iso-radicals.

Examples of saturated heterocyclic structures formed by R¹ and R², or R⁴ and R⁵, together with the nitrogen atom are pyrrolidino, piperidino, morpholino, piperazino, N-methylpiperazino and N-β-hydroxyethylpiperazino.

Alkyl radicals R³ are butyl, propyl, ethyl or, preferably, methyl.

Exampls of radicals R⁴ and R⁵ are the radicals stated above for R¹ and R² and furthermore ##STR4## alkylene-Z-alkylene-B¹ or unsubstituted or substituted phenyl or naphthyl, where m is 0 or 1, B is hydrogen or unsubstituted or substituted alkyl, Z is O, S or ##STR5## and B¹ is alkoxy or ##STR6##

B is hydrogen or, for example, CH₃, C₂ H₅, CH₂ C₆ H₅, C₂ H₄ OH or C₃ H₆ OH.

Specific examples of radicals in addition to those stated above for R⁴ and R⁵ are C₂ H₄ NH₂, C₃ H₆ NH₂, ##STR7## C₃ H₆ NHCH₃, C₂ H₄ N(CH₃)₂, C₂ H₄ N(C₂ H₅)₂, C₂ H₄ N(C₃ H₇)₂, C₂ H₄ N(C₄ H₉)₂, C₃ H₆ N(C₂ H₅)₂, C₂ H₄ N.sup.⊕ (CH₃)₃, C₃ H₆ N.sup.⊕ (CH₃)₃, C₃ H₆ OC₃ H₆ NH₂, C₃ H₆ OC₃ H₆ N(CH₃)₂, C₂ H₄ NHC₂ H₄ NH₂ or C₃ H₆ NHC₃ H₆ NH₂.

Anion A.sup.⊖ is an organic or inorganic ion, eg. chloride, bromide, sulfate, bisulfate, methylsulfate, aminosulfonate, perchlorate, benzenesulfonate, oxalate, maleate, acetate, hydroxyacetate, methoxyacetate, propionate, lactate, succinate, tartrate or methanesulfonate.

Compounds of the formula I can be prepared by converting a compound of the formula ##STR8## to the amide. The Examples which follow illustrate the preparation. Parts and percentages are by weight, unless stated otherwise.

The compounds of the formula I are useful for dyeing anionically modified fibers, for the preparation of printing pastes and printing inks, and for dyeing leather and plastics and in particular paper stocks. Surprisingly, these compounds can also be used for dyeing bleached (wood-free or low-wood) pulps in brilliant red hues. Bath exhaustion is very high.

Of particular industrial importance are compounds of the formula Ia ##STR9## where T is C₁ -C₄ -alkyl, T¹ is hydrogen or C₁ -C₄ -alkyl, T² is C₁ -C₄ -alkyl or cyclohexyl, T¹ and T², together with the nitrogen atom, form a saturated heterocyclic structure, T³ is hydrogen or methyl and A.sup.⊖ and R⁴ have the stated meanings.

T is particularly preferably C₂ H₅, T¹ is particularly preferably H, CH₃ or C₂ H₅, T² is particularly preferably CH₃, C₂ H₅ or C₆ H₁₁, R⁴ is particularly preferably branched alkyl of 3 to 13 carbon atoms, eg. ##STR10## CH(CH₃)C₂ H₄ CH(CH₃)₂, CH(CH₃)C₃ H₆ CH(CH₃)₂ or ##STR11## or C₅ -C₇ -cycloalkyl which is unsubstituted or substituted by hydroxyl or C₁ -C₄ -alkyl.

EXAMPLE 1

8.28 parts of the rhodamine dye of the formula I, in the form of the base, and 2.35 parts of benzylamine are introduced into 50 parts by volume of chlorobenzene. 3.06 parts of phosphorus oxytrichloride are run in over about 15 minutes, the temperature increasing to about 50° C. The reaction mixture is refluxed for 3 hours.

100 parts of water are added, after which distillation is continued until chlorobenzene no longer passes over. 25 parts of a 10% strength sodium hydroxide solution are then added, and the stirred mixture is left to cool. 8.5 parts of a crystalline product of the formula II are obtained, the product being filtered off under suction, washed with water and dried at 60° C.

The same results are obtained if chlorobenzene is replaced with chloroform, 1,2-dichloroethane, trichloroethylene, toluene, xylene or dichlorobenzene, and POCl₃ is replaced with an equimolar amount of PCl₃ or PCl₅. ##STR12##

The dye base of the formula II dissolves in dilute acetic acid with the formation of the quaternary salt with acetate as the anion.

EXAMPLE 2

8.28 parts of the dye base of the formula I (cf. Example 1) and 1.5 parts of methylammonium chloride in 50 parts by volume of 1,2-dichloroethane are reacted in the presence of 3.06 parts of phosphorus oxytrichloride in the course of 5 hours under reflux. The reaction mixture is worked up by a procedure similar to that described in Example 1 to give 8.0 parts of the dye base of the formula III ##STR13## where R₁ is H and R₂ is CH₃.

The procedure described in Example 2 was also used to obtain the dyes of the formula III which are characterized in the Table, methylammonium chloride being replaced with ethylammonium chloride, dimethylammonium chloride or diethylammonium chloride or the corresponding amines R₂ NH₂ :

    ______________________________________                                         Example R.sub.1 R.sub.2         λ max. (nm)                             ______________________________________                                         3       H       C.sub.2 H.sub.5 534                                            4       CH.sub.3                                                                               CH.sub.3        532.5                                          5       C.sub.2 H.sub.5                                                                        C.sub.2 H.sub.5 532                                            6       H       nC.sub.3 H.sub.7                                                                               534                                            7       H                                                                                       ##STR14##      534                                            8       H       nC.sub.4 H.sub.9                                                                               534                                            9       H                                                                                       ##STR15##      534                                            10      H                                                                                       ##STR16##      534                                            11      H                                                                                       ##STR17##      532                                            12      H                                                                                       ##STR18##      534                                            13      H       CH.sub.2 C.sub.6 H.sub.5                                                                       534                                            14      H       C.sub.2 H.sub.4 C.sub.6 H.sub.5                                                                534                                            15      H       C.sub.6 H.sub.5 530.5                                          16      H       C.sub.6 H.sub.12                                                                               534                                            17      H       C.sub.2 H.sub.4 OCH.sub.3                                                                      533.5                                          18      H       C.sub.3 H.sub.6 OCH.sub.3                                                                      534                                            19      H       C.sub.3 H.sub.6 OC.sub. 2 H.sub.5                                                              534                                            20      H                                                                                       ##STR19##      534                                            21      H       C.sub.3 H.sub.6 N(CH.sub.3).sub.2                                                              533.5                                          22      H                                                                                       ##STR20##      533                                            ______________________________________                                    

EXAMPLE 23

7.8 parts of the rhodamine dye base of the formula IV, where R₃ is N(CH₃)₂, are reacted with 1.6 parts of n-butylamine in 50 parts by volume of 1,2-dichloroethane, in the presence of 3.06 parts of phosphorus oxytrichloride, using a method similar to that described in Example 1. 6 parts of the dye base V, where R₃ is N(CH₃)₂ and R₄ is n--C₄ H₉, are obtained (λmax.: 541 nm). ##STR21## The compound of the formula IV, where R₃ is N(CH₃)₂, can be prepared as follows:

57 parts of 2-(2'-hydroxy-4'-dimethylaminobenzoyl)benzoic acid of the formula VI, prepared by a conventional method from m-dimethylaminophenol and phthalic anhydride, are dissolved in 410 parts of 96% strength sulfuric acid at room temperature. 30.2 parts of 3-ethylamino-p-cresol of the formula VII are added, after which the mixture is heated to 50° C., kept at this temperature for 3 hours and then discharged onto 1,100 parts of ice water. The crystalline precipitate is filtered off under suction, washed with 200 parts of water and then dissolved in 400 parts of water at about 70° C. The solution is brought to pH 11 with sodium hydroxide solution, the dye base of the formula VIII being precipitated in crystalline form. The product is filtered off under suction, washed with water and dried at 60° C. The yield is 52 parts. ##STR22##

The dyes of the formula V which are described in the Table were obtained by the same procedure:

    ______________________________________                                         Example   R.sub.3     R.sub.4   λ max. (nm)                             ______________________________________                                         24        N(CH.sub.3).sub.2                                                                          CH.sub.2 C.sub.6 H.sub.5                                                                 542.5                                          25        N(CH.sub.3).sub.2                                                                          C.sub.2 H.sub.4 C.sub.6 H.sub.5                                                          541                                            26        N(C.sub.2 H.sub.5).sub.2                                                                   n-C.sub.4 H.sub.9                                                                        546                                            27        N(C.sub.2 H.sub.5).sub.2                                                                   CH.sub.2 C.sub.6 H.sub.5                                                                 549.5                                          28        N(C.sub.2 H.sub.5).sub.2                                                                   C.sub.2 H.sub.4 C.sub.6 H.sub.5                                                          547                                            29        pyrrolidino n-C.sub.4 H.sub.9                                                                        545                                            30        pyrrolidino CH.sub.2 C.sub.6 H.sub.5                                                                 546.5                                          31        pyrrolidino C.sub.2 H.sub.4 C.sub.6 H.sub.5                                                          547                                            32        morpholino  n-C.sub.4 H.sub.9                                                                        544                                            33        morpholino  CH.sub.2 C.sub.6 H.sub.5                                                                 545                                            34        morpholino  C.sub.2 H.sub.4 C.sub.6 H.sub.5                                                          542.5                                          ______________________________________                                     

We claim:
 1. A compound of formula I: ##STR23## wherein A⁻ is an anion, R, R¹ and R² are each independently hydrogen, alkyl, cycloalkyl, alkyl substituted by hydroxyl, C₁ -C₁₃ -alkoxy, chlorine, cyano, phenyl, tolyl, chlorophenyl or methoxyphenyl or C₁ -C₄ -alkyl substituted cycloalkyl, or one of said R¹ or R² radicals is phenyl, or R¹ and R², together with the nitrogen atoms, form a pyrrolidino, piperidino, morpholino, piperazino, N-methylpiperazino or N-β-hydroxyethylpiperazino ring, R³ is hydrogen or C₁ -C₄ -alkyl, R⁴ and R⁵ independently of each other are alkyl, cycloalkyl, alkyl substituted by hydroxyl, C₁ -C₁₃ -alkoxy, chlorine, cyano, phenyl, tolyl, chlorophenyl or methoxyphenyl or C₁ -C₄ -alkyl substituted cycloalkyl, or aminoethyl, aminopropyl, amino(α-methyl)ethyl, methylaminopropyl, dimethylaminoethyl, diethylaminoethyl, dipropylaminoethyl, dibutylaminoethyl, diethylaminopropyl, aminopropoxypropyl, dimethylaminopropoxypropyl, aminoethylaminoethyl or aminopropylaminopropyl; or one of said R⁴ or R⁵ radicals is hydrogen, phenyl or naphthyl, or R⁴ and R⁵, together with the nitrogen atom, form a pyrrolidino, piperidino, morpholino, piperazino, N-methylpiperazino, or N-β-hydroxyethylpiperazino ring, n is 1, 2 or 3, X is hydrogen, chlorine, bromine, C₁ -C₄ -alkyl, C₁ -C₄ -alkoxy or nitro and Y is hydrogen or chlorine.
 2. The compound of claim 1, which has the formula: ##STR24## wherein T is C₁ -C₄ -alkyl, T¹ is hydrogen or C₁ -C₄ -alkyl, T² is C₁ -C₄ -alkyl or cyclohexyl, or T¹ and T², together with the nitrogen atom, form a pyrrolidino, piperidino, morpholino, piperazino, N-methylpiperazino, or N-β-hydroxyethylpiperazino ring, T³ is hydrogen or methyl and A⁻ and R⁴ have the stated meanings.
 3. The compound of claim 2, wherein T is C₂ H₅, T¹ is H, CH₃ or C₂ H₅, T² is CH₃, C₂ H₅ or C₆ H₁₁ and R⁴ is branched alkyl of 3-13 carbon atoms or is C₅ -C₇ -cycloalkyl or C₅ -C₇ -cycloalkyl substituted by hydroxyl or C₁ -C₄ -alkyl.
 4. The compound of claim 1, wherein said R, R¹ and R² groups are each selected from the group consisting of methyl, ethyl, propyl, butyl, pentyl, hexyl, octyl, decyl, dodecyl, tridecyl, 2-ethylhexyl, hydroxyethyl, hydroxypropyl, methoxyethyl, ethoxyethyl, propoxyethyl, butoxyethyl, methoxypropyl, butoxypropyl, methoxyethoxyethyl, ethoxyethoxyethyl, butoxyethoxyethyl, methoxyethoxy(α-methyl)ethyl, chloroethyl, cyanoethyl, benzyl, phenylethyl, methylbenzyl, chlorobenzyl, methoxybenzyl, dimethylbenzyl, cyclopentyl, cyclohexyl and methylcyclohexyl.
 5. The compound of claim 1, wherein R⁴ and R⁵ are selected from the group consisting of aminoethyl, aminopropyl, amino(α-methyl)ethyl, methylaminopropyl, dimethylaminoethyl, diethylaminoethyl, dipropylaminoethyl, dibutylaminoethyl, diethylaminopropyl, aminopropoxypropyl, dimethylaminopropoxypropyl, aminoethylaminoethyl and aminopropylaminopropyl. 